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When to plant Turnip in DeKalb County, IL

For Turnip in DeKalb County, the safe spring window opens around April 8 and closes around April 29. Last expected frost is April 22, first fall frost October 16, giving a 177-day growing season. A second sowing from August 7 to August 21 extends the harvest into fall.

When to Plant Turnip in DeKalb County, IL

DeKalb County, Illinois Zone 5b June

What to do in June

A quick June briefing for DeKalb County, Illinois gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 22
Avg. first frost October 16
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 15 hrs
  1. Collect turnip at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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Turnips are a fast-growing cool-season root vegetable with edible roots and greens. Baby turnips are sweet and tender while mature ones are more pungent.

DeKalb County, Illinois is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 16, giving you a growing season of approximately 177 days.

At an elevation of 1,332 feet, DeKalb County receives approximately 34.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Turnip during the growing season.

DeKalb County, IL (Zone 5b) Moderate season
177 days
Last Spring Frost April 22
177 growing days
First Fall Frost October 16

DeKalb County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Turnip Planting Risk Windows

Early Start (70% safe) ✓ Fits season (101 days to spare)
Transplant: Apr 16 🍅 Harvest: May 28 – Jul 2
Recommended (50%) ✓ Fits season (100 days to spare)
Transplant: Apr 22 🍅 Harvest: Jun 3 – Jul 8
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: May 9 🍅 Harvest: Jun 20 – Jul 25

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in DeKalb County

How your county's soil matches Turnip's growing requirements.

Soil pH

Your soil pH (6.2–7.2) overlaps with Turnip's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in DeKalb County is excellent for Turnip — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Turnip.

Organic Matter

Organic matter is excellent (5.1%) — Turnip will thrive.

How to Plant Turnip

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Turnip

5
successive plantings in your 177-day season

Sow every 4.6 weeks. Last sowing by Aug 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 07.

Turnip Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 919 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Turnip

Turnip needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Turnip Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in DeKalb County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Turnip Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Turnip needs ~762 GDD — county provides 2,699 GDD Excellent fit

Turnip Planting Timeline — DeKalb County, IL

Turnip Planting Calendar

Activity When Date Range
Direct Sow April 8 Apr 8 – Apr 29
Harvest May 20 May 20 – Jun 24
Fall Sowing August 7 Aug 7 – Aug 21

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Harvest
June Harvest
July
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

177 days in DeKalb County

Growing Tips for Turnip in DeKalb County

Direct sow Turnip outdoors after April 22 in DeKalb County when soil has warmed and frost danger has passed.

Your generous 177.0-day season in DeKalb County allows multiple plantings of Turnip. Sow every 20.0 days for continuous harvest.

Common pests for Turnip in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in early spring or late summer. Harvest when roots are 2-3 inches in diameter for best flavor. Both the roots and the greens are nutritious and edible.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Turnip in DeKalb County, IL?

DeKalb County is in Zone 5b with an average last frost of April 22. Plan your Turnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is DeKalb County, IL?

DeKalb County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 16.

When should I plant Turnip in DeKalb County, IL?

In DeKalb County, IL, plant Turnip after the last frost (around April 22) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is DeKalb County, IL for Turnip?

DeKalb County sits in USDA Zone 5b. Turnip grows reliably in zones 2a through 10b, so it's a good fit here.

Can Turnip grow in DeKalb County's climate?

Yes — Turnip grows well in DeKalb County's temperate climate. DeKalb County averages a 177-day frost-free season, with last frost around April 22 and first frost around October 16.

🌱

Your DeKalb County Garden Planner — Free

A 22-page printable planner built for DeKalb County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for DeKalb County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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